Technology for attaching facing system to insulation product

ABSTRACT

An insulation product includes an elongated batt of fibrous insulation material, and a facing adhered to a major surface of the batt. The facing is a coextruded polymer film of barrier and bonding (and preferably carrier) layers, with the bonding layer having a softening point lower than the softening point of the barrier layer. The bonding layer can include one or more of ethylene N-butyl acrylate, ethylene methyl acrylate, low density polyethylene and ethylene ethyl acrylate. When the facing has been heated to a temperature above the softening point of the bonding layer, but below the softening point of the barrier layer, the facing is adhered to the batt by the attachment of the bonding layer to the fibers in the batt due to the softening of the bonding layer. The heating can be either conduction heating or ultrasonic heating. For ultrasonic heating, the bonding layer is resonant at a different ultrasonic frequency than the barrier layer. The insulation product can be singly-faced or doubly-faced, and the edges of the double-facing can be joined to form an encapsulated product.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

This invention relates to fibrous insulation products, and in particularthose insulation products of the type suitable for insulating buildings.More specifically, this invention pertains to insulation products havinga facing system for providing a vapor barrier and/or for assisting inhandling the insulation products. The invention also relates totechnology for attaching the facing system to insulation products

BACKGROUND OF THE INVENTION

Fibrous insulation is typically formed by fiberizing molten material anddepositing the fibers on a collecting conveyor. Typically the fibers forinsulation products are mineral fibers, such as glass fibers, althoughsome insulation products are made of organic fibers, such aspolypropylene and polyester. Most fibrous insulation products contain abinder material to bond the fibers together where they contact eachother, forming a lattice or network. The binder gives the insulationproduct resiliency for recovery after packaging, and provides stiffnessand handleability so that the product can be handled and applied asneeded in the insulation cavities of buildings. During manufacturing theinsulation is cut into lengths to form individual insulation products,and the insulation products are packaged for shipping to customerlocations.

One typical insulation product is an insulation batt, usually about 8feet long, and generally suitable for use as wall insulation inresidential dwellings, or as insulation in the attic and floorinsulation cavities in buildings. The width of insulation batts designedfor wall cavities is set to typical insulation cavity widths, such asabout 14½ inches or 22½ inches for stud spacings of 16 and 24 inches,respectively. Some insulation products have a facing on one of the majorsurfaces. In many cases the facing acts as a vapor barrier, and in someinsulation products, such as binderless products, the facing gives theproduct integrity for handleability. Faced insulation products areinstalled with the facing placed flat on the edge of the insulationcavity, typically the interior side or edge of the insulation cavity.

Insulation products where the facing is a vapor barrier are commonlyused to insulate wall, floor or ceiling cavities that separate a warminterior space from a cold exterior space. The vapor barrier is usuallyplaced to prevent moisture-laden air from the warm interior of thedwelling from entering the insulation. Otherwise, the water vapor in thewarm interior air would enter the insulation material and then cool andcondense within the insulation. This would result in a damp insulationproduct, which is incapable of performing at its designed efficiency. Inwarm climates it is sometimes preferable to install the vapor barrier onthe exterior side of the insulation cavity to reduce the amount of vaporentering the building during the air conditioning season. The stiffnessof typical asphalt-kraft-faced insulation enhances the difficulty ofsuch installations.

There are some insulation product requirements that call for insulationthat is not vapor impermeable, but rather allows water vapor to passthrough. For example, retrofit insulation products designed for addingadditional insulation material on top of existing attic insulationshould not have a vapor barrier. Also, insulation for wall cavitieshaving a separate fall wall vapor barrier, such as a 4.0 milpolyethylene film on the interior or warm side of the wall, do notrequire a vapor barrier on the insulation product itself.

Encapsulation of fibrous glass batts for handling purposes is known. TheSchelhom patent (U.S. Pat. No. 5,277,955 to Schelhom et al.) disclosesan encapsulated batt with an encapsulation material adhered with anadhesive that can be applied in longitudinal stripes, or in patternssuch as dots, or in an adhesive matrix. The Schelhorn et al. patent alsodiscloses that an alternative method of attachment is for the adhesivelayer to be an integral part of the encapsulation film, which, whensoftened, bonds to the fibers in the batt.

The Syme patent (U.S. Pat. No. 5,733,624 to Syme et al.) discloses amineral fiber batt impregnated with a coextruded polymer layeringsystem, and the Romes patent (U.S. Pat. No. 5,746,854 to Romes et al.)discloses a method for impregnating a mineral fiber batt with acoextruded film. Both of these patents disclose attaching the coextrudedfilm to the batt by heating at least the coextruded film if not also thebatt. The heat energy is primarily transferred by conduction to the filmas the film passes against a heated cylinder. Optional radiant infrared(IR) heaters are also disclosed as a supplemental source of heat energy.

Attaching the coextruded film in this manner has some disadvantages.Heating cannot be abruptly terminated or quickly varied. The heatedcylinder of the Syme patent and the Romes patent is a large reservoir oftemperature that cannot change its temperature quickly. In addition,target areas to be heated cannot be energized with great precision.Because of the need to come in close proximity to the hot surface of theheated cylinder, areas near the targeted areas are also inadvertentlyheated, creating a significant penumbra of unwanted temperatureelevation.

Vapor barriers for insulation products are typically created with alayer of asphalt in conjunction with a kraft paper or foil facingmaterial. The asphalt layer is applied in molten form and it is pressedagainst the fibrous insulation material before hardening to bond thekraft facing material to the insulation material. This asphalt and kraftpaper system has the advantage of being relatively inexpensive. However,this facing system lacks flexibility because the asphalt/kraft layer isstiff, and working with the stiff asphalt/kraft facing slows down theinstallation of the insulation products. Also, cutting the facingwithout tearing the kraft paper is difficult in cool ambienttemperatures because the asphalt can be brittle. Further, and theasphalt material is sticky in hot ambient temperatures, resulting in agumming up of the cutting tool.

Even though the batts are manufactured to fit typical insulationcavities, many of the insulation cavities in buildings are ofnonstandard dimensions. Window frames, door jambs, vent pipes, air ductsand electrical conduit are some of the typical obstructions that changethe shape of the insulation cavity. During the process of installing thebatts a significant portion of the batts must be cut to fit these nonstandard insulation cavities. In some dwellings up to 50 percent of theinsulation cavities are nonstandard. Therefore, an important attributeof a faced building insulation product is the ease with which the facingcan be cut and the ability of the facing to be placed flat on the edgeof the insulation cavity after the facing has been cut. If the facing isnot flat on the edge of the insulation cavity, the vapor barrier will beonly partially effective. Further, insulation customers desire a smoothfacing that is relatively flat on the edge of the insulation cavity.

In view of the above problems with currently available insulationproducts, it would be advantageous if there could be developed a facedinsulation product (and technology for the attachment thereof) having afacing material that can be easily cut to fit into nonstandardinsulation cavities, and having a facing material that is flexibleenough that it can accommodate faster installation of the cut insulationproduct into nonstandard insulation cavities with the facing in a flatcondition at the edge of the insulation cavity.

SUMMARY OF THE INVENTION

The invention is directed, in part, to an insulation product comprisingan elongated batt of fibrous insulation material, and a facing adheredto a major surface of the batt, wherein the facing is a coextrudedpolymer film of barrier and bonding layers, with the bonding layerhaving a softening point lower than the softening point of the barrierlayer, where the bonding layer can include one or more of ethyleneN-butyl acrylate, ethylene methyl acrylate ethylene ethyl acrylate, lowdensity polyethylene (LDPE) and ethylene vinyl acetate, and wherein thefacing has been heated to a temperature above the softening point of thebonding layer, but below the softening point of the barrier layer,whereby the facing is adhered to the batt by the attachment of thebonding layer to the fibers in the batt due to the softening of thebonding layer.

The invention is also, in part, directed to an insulation productcomprising an elongated batt of fibrous insulation material, and afacing adhered to a major surface of the batt, wherein the facing is acoextruded polymer film of barrier, carrier and bonding layers, with thebonding layer having a softening point lower than the softening point ofthe barrier layer, and with the carrier layer being positioned betweenthe barrier and bonding layers, wherein the facing has been heated to atemperature above the softening point of the bonding layer, but belowthe softening point of the barrier layer, whereby the facing is adheredto the batt by the attachment of the bonding layer to the fibers in thebatt due to the softening of the bonding layer.

The invention is also, in part, directed to a method of making aninsulation product comprising positioning a facing in contact with amajor face of an elongated batt of fibrous insulation material, whereinthe facing is a coextruded polymer film of barrier and bonding layers,with the bonding layer including one or more of ethylene N-butylacrylate, ethylene methyl acrylate, LDPE and ethylene ethyl acrylate,and with the bonding layer having a softening point lower than thesoftening point of the barrier layer, and heating the facing to atemperature above the softening point of the bonding layer, but belowthe softening point (or bond initiation temperature, BIT) of the barrierlayer, while maintaining the facing in contact with the batt to softenthe bonding layer to an extent sufficient attach the bonding layer tothe fibers in the batt and thereby adhere the facing to the batt.

The invention is also, in part, directed to a method for installing aninsulation product and a correspondingly insulated studded wall. Themethod comprises providing an insulation product including an elongatedbatt of fibrous insulation material and a facing adhered to a majorsurface of the batt. The facing is a coextruded polymer film of barrierand bonding layers, with the bonding layer having a softening pointlower than the softening point of the barrier layer. The facing has beenheated to a temperature above the softening point of the bonding layer,but below the softening point of the barrier layer, whereby the facingis adhered to the batt by the attachment of the bonding layer to thefibers in the batt due to the softening of the bonding layer. The facinghas no flanges. The method further comprises installing the insulationproduct in an insulation cavity by pressing the insulation product intoplace between opposed structural members. Alternatively, the copolymerfacing can be installed as a separate continuous sheet across thecavities in the studded wall.

The invention is also, in part, a recognition that ultrasonic bonding offilms can be achieved without the high pressures and hard opposingsurface (relative to the ultrasonic radiation source) of knownultrasonic welding technology.

The invention is also, in part, directed to a method (and an apparatusto implement the method) for attaching a facing to a mineral fiber batt,the method comprising: providing the batt; providing the facing;positioning the facing to be in contact with the batt; andultrasonically energizing the facing sufficient to soften a portion ofthe facing onto fibers of the batt. Preferably, the facing is acoextruded polymer film, the first layer of which is a bonding layerthat is resonant at a first frequency of ultrasonic radiation. Thesecond layer is preferably not resonant at the first frequency. Morepreferably, the second layer is a carrier layer.

The invention is also, in part, directed to an apparatus for attachingat least two facings to a mineral fiber batt, the apparatus comprising:a first facing source; a first roller arranged to place a first facingfrom the first facing source into contact with a first side of the batt;a first heating source operable to heat a region through which passesthe first facing while in contact with the batt, the heating by thefirst heating source being sufficient to soften a portion of the firstfacing onto fibers of the batt; a second facing source; a second rollerarranged to place a second facing from the second facing source intocontact with a second side of the batt; and a second heating sourceoperable to heat a region through which passes the second facing whilein contact with the batt, the heating by the second heating source beingsufficient to soften a portion of the second facing onto fibers of thebatt.

The foregoing and other objectives of the present invention will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus do not limit thepresent invention.

FIG. 1 is a schematic view in perspective of typical nonstandard wallinsulation cavities.

FIG. 2 is a schematic perspective view of the wall cavities of FIG. 1,partially cut away and insulated with typical prior art insulationproducts.

FIG. 3 is a schematic perspective view of a faced insulation productaccording to the present invention, with a portion cut away.

FIG. 4 is a schematic perspective view of the insulation product of FIG.3, partially cut away and installed into the wall cavity of FIG. 1.

FIG. 5 is a schematic perspective view, similar to FIG. 3, of anotherembodiment of the insulation product according to the present invention,having no side edge extensions or flanges.

FIG. 6 is a schematic perspective view of another embodiment of theinsulation product according to the present invention, with a portioncut away, and having encapsulation material on the rear and sides of theinsulation product.

FIG. 7 is a schematic perspective view of a first apparatus formanufacturing the insulation products according to the invention.

FIG. 8 is a schematic perspective view illustrating a faced insulationproduct of the invention, having been slit longitudinally to provide apartial bate suitable for insulating the nonstandard insulation cavityof FIG. 1.

FIG. 9 is a schematic cross-sectional view in elevation illustrating thevarious layers of a multilayer facing film of the invention.

FIG. 10 is a schematic perspective view of a second apparatus formanufacturing the insulation products of the invention.

FIG. 11 is a schematic perspective view of a third apparatus formanufacturing insulation products according to the invention.

FIG. 12 depicts an aspect of FIG. 13 in more detail.

FIG. 13 depicts a simplified schematic perspective view of a fourthembodiment for manufacturing an insulation product according to theinvention.

The appended drawings are not necessarily drawn to a consistent scale.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

While the description and drawings disclose insulation products offiberglass insulation, it is to be understood that the insulationmaterial can be any compressible fibrous insulation material, such asrock wool, polypropylene or polyester.

As shown in FIG. 1, a typical wall structure, indicated generally at 10,includes a bottom plate 12 on which rests a plurality of studs 14. Thebottom plate, studs and a top plate, not shown, define the four sides ofinsulation wall cavities 16, 18 and 20. The front and the back of thewall cavity are typically made of drywall on the interior side and foamsheathing on the exterior, both not shown. Wall cavity 16 can beconsidered to be a non-standard wall cavity since it has a width muchnarrower than that of a typical wall cavity. Insulating wall cavity 16will require cutting the insulation product to a narrower width.Insulation cavity 18 is also difficult to insulate since there is a ventpipe 22 running vertically within the cavity, making cavity 18 anonstandard cavity. Insulating cavity 18 will usually require cutting aninsulation batt longitudinally into two narrower insulation pieces, notshown in FIG. 1. For insulation purposes, insulation cavity 18 can beconsidered to comprise two partial cavities, indicated at 24 and 26,each of which must be insulated. Insulation cavity 20 is also anonstandard cavity since the insulation material must be positionedaround an electrical outlet box 28 and conduit 30. Installation of theinsulation material around these obstructions requires cutting the battto fit it around the obstruction. Other typical obstructions includedoor jambs, window frames, air ducts, and water pipes, all not shown.

As shown in FIG. 2, a typical flanged prior art insulation product hasbeen cut to a narrow partial insulation product 32 and installed ininsulation cavity 16. Also another prior art insulation product 34 hasbeen installed in nonstandard wall cavity 18, and another similar priorart insulation product 36 has been installed in non standard wall cavity20. The rear of the insulation cavities 16, 18 and 20 is defined byexterior sheathing 38. It can be seen that in order to install theinsulation product 34 into the nonstandard insulation cavity 18, theinsulation product was split longitudinally into two partial batts 40and 42. Further, the facing material 44, which is a kraft paper bondedto the fibrous insulation material by asphalt, has been cut to form thefacing for the two partial batts 40 and 42.

The facing material of insulation product 34 is attached to the studs 14by staples 46. Although the stapling of the flanges of the insulationproduct 32 can be to the ends of the studs, it is preferred that theflanges be side stapled to the sides of the studs. This procedure leavesthe ends or exposed edges of the studs smooth for a potentially betterapplication of the drywall. Unfortunately the side or inset stapling ofthe flanges requires the asphalt/kraft facing to be bent, creating avalley-shaped depression or crease 48 running the length of theinsulation product. This crease 48 is undesirable because the insulationmaterial is prevented from flat, smooth contact with the front edge ofthe insulation cavity, and additionally the insulation material can beovercompressed, thereby lowering the insulation value of the insulationproduct. Also, the stiff asphalt/kraft facing 44 cannot always bestapled flat against the side of the stud 14, leaving fishmouth oropenings 50 between the facing and the sides of the studs.

The insulation of the two partial cavities also presents a problem. Itcan be seen that the portions of the facing material on the two partialbafts 40 and 42 are slightly separated, forming a gap 52 through whichwater vapor can travel into the insulation material of the batt. The gap52 is typically caused because cutting the batt and facing material isdifficult when the facing material is an asphalt/kraft paper system, asshown in FIG. 2. The opening 50 and the gap 52 are undesirable aspectsof the insulation job illustrated in FIG. 2.

The installation of prior art insulation product 36 into insulationcavity 20 involved cutting out a portion of the fibrous insulationmaterial around the electrical outlet box 28. If the insulation wereinstalled without cutting out for the electrical 20 outlet box, theinsulation would be over compressed, and might even affect the drywall.Cutting the insulation to accommodate the outlet box required a portionof the flange to be removed. With a conventional asphalt/kraft facing itis difficult to obtain a good seal if a portion of a flange is missing.The difficulty in obtaining a good seal because of the cutout for theoutlet box and other obstructions, and because of other imperfections inthe structure, results in the openings 50 between the facing material 44and the stud walls 14. Because of the stiffness of the asphalt/kraftfacing combination, openings similar to openings 50 can occur even withstandard insulation cavities having no obstructions in situations wherethe studs are uneven or out of alignment.

As shown in FIG. 3, the insulation product of the invention, indicatedgenerally at 60, is comprised of an elongated batt 62 of fibrousinsulation material, and a facing 64 adhered to a major surface, frontsurface 66 of the batt 62. The fibrous insulation material is preferablyfibrous glass having a density within the range of from about 0.3 toabout 15.0 pounds per cubic foot (pcf), although other densities can beused. Also, other fibers, such as mineral fibers of rock, slag orbasalt, can be used as well as organic fibers such as the polymer fiberspolypropylene, polyester and polysulfide, as well as other organicfibers. The fibers may be bonded together with a binder material, suchas a urea phenol-formaldehyde commonly used with fiberglass insulation,or the glass fibers can be binderless. Binderless glass fibers will becapable of much greater movement within the insulation pack structurethan fibers in a pack structure with binder. As used in the presentspecification and claims, the term “binderless” means the -absence ofbinder materials or the presence of only small amounts of such bindermaterials, amounting to no more than one percent by weight of theinsulation product. Addition of suppressants, e.g. oils, for dustcontrol or other purposes is not considered a binder. An example of anencapsulated binderless product is disclosed in the U.S. Pat. No.5,277,955 to Schelhom et al., as mentioned above.

The facing 64 is a dual layer facing comprising a coextruded polymerfilm of a barrier layer 70 and a bonding layer 72. The purpose of thebarrier layer 70 is to provide a tough but flexible outer surface forthe insulation product 60. The barrier layer 70 is a vapor barrier,although in other embodiments of the insulation, where the insulationproduct does not need to provide vapor protection, the barrier layer canbe vapor porous. Although the preferred form of the facing 64 is acoextruded polymer film, it is to be understood that in other forms ofthe invention the facing is made of a dual layer film that is notcoextruded, but rather formed in another manner, such as by as adhesive,heat lamination or chemical bonding.

The softening temperatures of the barrier layer 70 and bonding layer 72are different by about 100° F. with the bonding layer having a softeningpoint lower than the softening point of the barrier layer. During themanufacturing process the facing 64 is adhered to the batt 62 by heatingthe facing to a temperature above the softening point of the bondinglayer, but below the softening point of the barrier layer. The facing isadhered to the batt 62 by the attachment of the bonding layer 72 to thefibers in the batt due to the softening of the bonding layer.

A preferred material for the barrier layer is a high densitypolyethylene (HDPE) film having a softening point within the range offrom about 250 to about 280° F., and most preferably about 275° F. Highmolecular weight HDPE can also be used, but a greater cost. Anothermaterial suitable for the barrier layer is a polypropylene film having asoftening point within the range of from about 330 to about 390° F.Other polymer films, such as polypropylene, polyester and polystyrenecould also be used.

A preferred material for the bonding layer is a film of one or more ofethylene N-butyl acrylate (Et-BA), ethylene methyl acrylate (EMA),ethylene ethyl acrylate (EEA), low density polyethylene (LDPE) andethylene vinyl acetate (EVA). These materials are available from NewtechPlastics, Inc., Covington, Ohio, and they can be used alone, incombination with each other, or in combination with other materials,such as a low melt polyethylene material. The softening points of thesematerials are within the range of from about 100 to about 200° F., andmost preferably within the range of from about 120 to about 180° F.Preferably these ethylene acrylate materials are synthesized using ametallocene catalyst to lower the softening point. Another materialpotentially useful for the low melt bonding layer is a low melt or lowdensity polyethylene, preferably synthesized using a metallocenecatalyst to lower the softening point.

The difference in softening temperatures for the barrier layer and thebonding layer is preferably within the range of from about 50 to about225° F., and for an HDPE/ethylene acrylate system (i.e., ethyleneN-butyl acrylate, ethylene methyl acrylate and ethylene ethyl acrylate),the temperature difference is about 140° F. One of the great advantagesof the HDPE/ethylene acrylate facing system of the invention is that thefacing and insulation product can be cut easily over a broad temperaturerange. The bonding layer 72 is readily cuttable at even such warmtemperatures as about 110° F., and will not leave a gummy residue on thecutting tool. The facing does not soften at temperatures less than about110° F., and is not brittle at temperatures greater than about 30° F.Another advantage of the faced insulation product 60 of the invention isthat the facing 64 is more flexible than a conventional asphalt/kraftpaper facing. As measured by ASTM test D-1388 the flexural rigidity ofthe facing of the invention is preferably less than 500 gm cm, whereasthe flexural rigidity of standard asphalt/Kraft facing is greater thanabout 2000 gm cm. Further, the elastic (tangent) modulus of the facing64 of the invention, as measured by ASTM D-882, is within the range offrom about 25,000 to about 200,000 pounds per square inch (psi).Typically, the elastic modulus of the facing of the invention is about100,000 psi.

In its most preferred form the facing is a multilayer film 78, as shownin FIG. 9, comprising a barrier layer 80, a bonding layer 82 and acarrier layer 84. The barrier layer 80 and bonding layer 82 can besimilar to the HDPE and ethylene acrylate (i.e., ethylene N-butylacrylate, ethylene methyl acrylate and ethylene ethyl acrylate) layers70 and 72, respectively. The carrier layer can be a linear low densitypolyethylene (LLDPE) with a softening point of about 230° F. or a highdensity polyethylene (HDPE), and the carrier layer can be reinforced byany suitable material. Using a carrier layer is particularlyadvantageous where the difference in softening temperatures between thebarrier layer and the bonding layer is great. The carrier layer providesan insulative barrier between the barrier layer and the bonding layerduring the coextrusion of the polymer film sufficient to improve thepermissible difference in softening temperatures between the barrierlayer and the bonding layer, preferably by at least 30° F. Anotheradvantage of using a carrier layer is that it allows separation of thefunction of the vapor barrier quality of the barrier layer and theoutside surface of the facing as follows: the carrier layer (i.e., themiddle layer of the three layers) can be configured to be the actualvapor barrier layer, and the outside layer can be a high frictionsurface that is not necessarily a vapor barrier, but is a surfacedesigned for good printability. High density polyethylene may be tooslippery for good printing.

In another embodiment, not shown, the multilayer facing film includesfour individual layers, two HDPE layers, a carrier layer, and a bondinglayer. In yet other embodiments, the number of layers can be up toeleven or greater.

When exposed to fire, the facing on a fibrous pack insulation productpreferably will shrink and pull away from the fibrous pack. By pullingaway, the facing retards the spread of the flames. Preferably, the rateat which the facing shrinks and pulls away, i.e., the debonding rate,should be small below about 150° F., and should be large above about180° F., especially in the range of about 170-180° F. The embodiments ofthe invention that emphasize shrinking and pulling away of the facingpreferably form the bonding layer of EMA, EEA, Et-BA, Surlyn orlow-melt-temperature polyethylene. Where Surlyn® (a type of ioniccopolymer marketed by DuPont) is used as the bonding layer material, aflame spread (FS) has been achieved, which is comparable to conventionalfoil-faced products.

The shrinkage of the facing does not occur instantly, so anotherembodiment of the invention adds a fire retardant layer to themultilayer facing. The fire retardant layer retards the spread of flamesduring the time it takes for the facing to unbond and then shrink. Wheresuch a layer includes, e.g., antimony oxide and a halogen, a low FSrating has been achieved. A phosphate-based fire retardant can also beused. A multilayer facing that includes a Surlyn bonding layer and afire retardant layer should achieve an even lower FS rating.

Another embodiment of the invention selects the bonding layer so thatflanges formed from it will bond together when overlapped. When aflanged insulation product is installed in a studded wall cavity, theflanges are typically stapled to the studs. A stud located betweenneighboring cavities will typically have the flange from the insulationin one cavity stapled over the top of a flange from the insulation inthe other cavity. The coextruded film facing according to the inventioncan be formulated so that the bonding layers, over time due to thepressure of the overlying gypsum wallboard, will bond together whenoverlapped as described above.

In some northern areas, the building code requires that a separatecontinuous vapor barrier of thick polyethylene film be stapled andbonded with an adhesive over the installed (typically unfaced)insulation products.

According to the invention, the separate continuous vapor barrier ispreferably made of a copolymer film as discussed herein rather thanthick polyethylene film.

Alternatively, the insulation products incorporating the coextruded filmfacing according to the invention eliminate the need for such a discretebarrier because the individual facings bond together, especially if theoverlapped flanges are heated, e.g., with a heat gun or a heated roll.As a further alternative, the bonding layer can be formulated to beslightly tacky when cooled so as to enhance the attachment of theoverlapped flanges.

In another embodiment, an uppermost layer of the coextruded film facingis coated with metal and another layer is, or preferably several layers(to prevent pinholes in different layers from aligning) are, chosen tofinction as a vapor barrier layer. In appearance, this product willappear like a conventional foil-scrim-kraft (FSK) facing. This similarappearance of this embodiment will ease its entry into the market forFSK faced-insulation products. Though similar in appearance, such aproduct has superior vapor impermeability and mechanical strengthrelative to an FSK faced-product.

The facing 64 for the insulation product 60, and the facing 78 for themultilayer product both have an overall thickness, before the bondingstep, within the range of from about 0.4 to about 4 mils (about 10 toabout 100 microns), and preferably within the range of from about 0.5 toabout 1.5 mils (about 12.5 to about 37.5 microns). The two layers of thetwo-layer facing 64 preferably have equal thicknesses. For the multiplefacing 78, preferably each of its three layers is roughly one-third ofthe thickness of the facing. Individual thickness could bedifferent—example ¼, ¼ and ½.

As shown in FIG. 4, the insulation product 60 of the invention isapplied into nonstandard insulation cavities 16, 18 and 20. In theinsulation cavity 18 the insulation product has been divided or cut intopartial batts in order to fit around the vent pipe 22. Because of theflexibility and cutability of the facing 64, however, the only evidenceof the fact that the insulation product 60 is divided into two partialbatts is the seam 88 in the facing 64. This seam can be of minimalwidth, with practically no gap, as shown. Further, in contrast to thejagged gap 48 in the prior art cut asphalt/kraft facing 44 illustratedin FIG. 2, the seam 88 is relatively straight. In a similar manner, thecutting of the insulation product 60 to accommodate the electrical box28 can be accomplished without a seam. The insulation of cavities 16, 18and 20 with the insulation product 60, having the flexible facing 64,lends itself to a smooth appearance for the insulation product, and thefriction fit of the insulation product 60 enables installation withoutthe need for staples or other fasteners. Optionally, the seams 88 can becovered with tape to provide an absolute vapor barrier, but this shouldnot usually be necessary with the facing of the invention.

As shown in FIGS. 3 and 4, the facing 64 can be provided with extensionflaps 92 that can be tucked between the insulation product 60 and thestuds 14 to provide a 25 better vapor seal at the side edges of theinsulation product. The conventional asphalt-kraft facing is too stiffto permit such tucking, as a practical matter. The extension flaps 92could be used for stapling purposes, and therefore should also beconsidered stapling flanges. Preferably, the extension flaps extendabout ½ to 1 inch beyond the side edges of the batt. When the facing isa coextruded dual or tri-layer film having a low softening point bondinglayer on side facing the fibrous insulation batt, the difference insoftening points and coefficients of thermal expansion between the twolayers causes a curling of the extension flap toward the insulationmaterial. This curling helps provide a good seal when the extension flapis tucked between the facing and the stud.

A particular advantage of the insulation product and method of theinvention is the reduction in installation time for the insulation. Theelimination of the stapling of flanges for the product of the inventionsignificantly reduces the installation time, with the installation timeof the product of the invention being at least 10 percent faster, andpossibly up to 50 percent faster than standard asphalt/kraft facedinsulation. The time savings come from elimination of the staplingoperation and eliminating the use of the stiff kraft paper that is hardto handle and install in the wall.

As shown in FIG. 5, another embodiment of the invention is similar inall respects to the insulation product illustrated in FIG. 3 except thatthere are no extension flaps.

In an alternate embodiment of the invention illustrated in FIG. 6, aninsulation product 94, has a facing 96, similar to the facing 64, on onemajor surface of the batt 98. This insulation product is provided withan encapsulation film 100 on the side edges 102 and rear major face 104of the batt. The encapsulation film can be attached to the fibrous battin any suitable manner, such as by an adhesive layer or strip. Forexample, a strip of hot melt adhesive can be applied in liquid formduring manufacture of the insulation product. For example, U.S. Pat. No.5,277,955 to Schelhom et al. discloses an encapsulated batt with anencapsulation material adhered with an adhesive that can be applied inlongitudinal stripes, or in patterns such as dots, or in an adhesivematrix. Alternatively, the encapsulation film can be securely bonded tothe entire surface of the side edges and the rear major surface, such asby using a multilayer coextruded film similar to the facing 64. Such afilm might be, for example, a dual film of HDPE and polyethylene (PE),with a thickness within the range of at least about 0.5 to about 0.8mils if not in range of about 0.3 to 1.5 mils. Although the embodimentof the invention shown in FIG. 6 includes encapsulation on the sideedges and rear major surface of the batt 98, it is to be understood thatanother embodiment of the invention, not shown, provides encapsulationmaterial on the rear surface only, with the side edges lacking theencapsulation material.

The insulation product 94 optionally can be provided with an opening 106in the side edge of the facing 100 to expose the glass fibers in thebatt 98. The glass fibers inherently have high friction component, andtherefore the opening 106 provides a friction enhancing aspect of thebatt to aid in the friction fit application of the insulation product 94into insulation cavities. Another friction enhancing element is theaddition of friction surface treatment, such as a semi-tacky coating, tothe side edge of the facing 100.

The encapsulation material can be applied to the insulation batt by anysuitable 15 process. Apparatus suitable for directing and guiding theencapsulation material onto the glass fiber pack is disclosed in U.S.Pat. No. 5,545,279 to Hall et al., the entirety of which is herebyincorporated by reference. As shown in FIG. 7, a pack 110 of glassfibers is being carried on a conveyor 112. The manufacture of the glassfiber pack 110 is well known technology, and those skilled in the artwill be aware of several conventional methods for producing glass fiberpacks. The glass fiber pack is preferably a light density insulationmaterial, having a density within the range of from about 0.3 to about1.0 pounds per square foot (pcf). The glass fiber pack can be bondedwith a binder material, such as a urea phenol-formaldehyde binder, as iswell known in the art. Alternatively, the glass fiber pack can bebinderless.

A sheet of the facing material 64 is payed out from roll 114 anddirected into contact with the glass fiber pack 110. The facing material64 is pressed into forceful contact with the pack by the action ofjournaled pressing rolls 116 and 118, which compress the glass fiberpack by a ratio of up to about 25:1, and preferably about 5:1. Theamount of compression needed will be a function of the density. Theupper pressing roll 116 is heated so that the temperature of the facing64 will increase to a point above the softening point of the bondinglayer. The heating of the roll 116 can be accomplished in a variety ofways, such as by electrical resistance heating or by the circulation ofhot oil. The combination of the softened bonding layer and the extremepressure applied by the two pressing rolls 116 and 118 causes thebonding layer to firmly bond the barrier layer to the glass fiber pack110. An alternative method of heating the bonding layer is with aninfrared heater 120, as shown. Such a heater would have to be positionedimmediately upstream of a pair of pressing rolls, not shown, similar torolls 116 and 118, so that the softened bonding layer could be pressedinto the fibrous batt and be integrally bonded to the batt.Alternatively, ultrasonic, laser and microwave bonding can be used. Thealternative of ultrasonic bonding will be discussed in more detail belowrelative to FIG. 10. Optionally, a cooling section, not shown, can beused to cool the softened layer after the bonding process.

As also shown in FIG. 7, the remainder of the surface of the fibrouspack 110, i.e., the side edges 102 and the rear major face 104 can beencapsulated with encapsulation material or film 100 which can besupplied by encapsulation film roll 122. The film 100 can be appliedusing a folding shoe 124, an example of which is disclosed in theabove-identified U.S. Pat. No. 5,545,279 to Hall et al. As disclosedabove, the encapsulation film can be bonded with small amounts ofdiscrete adhesive bands. The adhesive can be applied in a variety ofways, such as by an adhesive nozzle 126, supplied with an appropriateadhesive from a source, not shown. In the alternative, the encapsulationfilm 100 can be securely bonded to the entire surface of the side edgesand the rear major surface with a multilayer coextruded film similar tothe facing 64, as disclosed above. Also, it is to be understood that theencapsulation material can be applied just to the rear surface, leavingthe side edges unencapsulated.

As shown in FIG. 8, a faced insulation product 60 of the invention hasbeen slit longitudinally to provide partial batts 130 and 132 suitablefor insulating nonstandard insulation cavities. The insulation product60 is faced with the facing 64 of the invention, but there is noencapsulation material. The insulation product is a bindered product,and therefore the partial batts 130 and 132 will maintain their shapeand handleability even when cut. Either of the partial batts is suitablefor insulating nonstandard insulation cavities, such as the partialcavity 26 shown in FIG. 1, or such as the narrow cavity 16 shown in FIG.1.

FIG. 10 is a schematic perspective view of a second apparatus formanufacturing the insulation products of the invention. FIG. 10 issimilar to FIG. 7. The following discussion will concentrate on thedifferences between FIG. 10 and FIG. 7. The greatest difference is that,in FIG. 10, the energy used to melt the facing material, e.g., acoextruded polymer, 64 is supplied as ultrasonic energy rather than viaconduction heating. This has the benefit that the energy can be appliedprecisely to a desired region, i.e., localized, without the unavoidableheat penumbra associated with conduction heating. Ultrasonic heating issimilarly more selective than infrared (IR) heating. Moreover,ultrasonic energization can be turned on and off abruptly with little tono phase lag. In contrast, the apparatus needed to implement conductionheating cannot be cooled or heated quickly.

In FIG. 10, the heated pressing roll 116 and the complimentary pressingroll 118 have been replaced by an unheated pressing roll 116A and itscomplimentary unheated pressing roll 118A. Together, they form a firstnip or pinch. An optional, but preferred, second pinch is provided byunheated pressing rolls 116B and 118B. The first and second nips areseparated by a distance sufficient to accommodate at least a firstultrasonic radiation source 128A, located above the facing material 64.Preferably, the distance is sufficient to also accommodate a secondultrasonic radiation source 128B, located above the facing material 64.Second source 128B is preferably considered to be a redundant backup tothe first source 128A so that if the first source 128A fails or must beserviced, the entire production line does not have to be incapacitated.

Alternatively, a pair of ultrasonic radiation sources 128C and 128Dcould be located below the fibrous pack or batt 110. The lower locationof the sources 128C and 128D is less preferred than the upper locationof the sources 128A and 128B because the ultrasonic radiation musttravel through the fibrous pack 110 to reach the facing material 64. Inaddition, the effects of gravity tend to keep the sources 128A and 128Bcleaner than the sources 128C and 128D. Also alternatively, the sources128C and 128D could be replaced with rollers.

In operation, the first nip (between the rollers 116A and 11 8A)compresses the facing material 64 against the fibrous pack 110 by aratio of up to 25:1, and preferably about 5:1. The compressed pack 110and facing material 64 pass before the first ultrasonic radiation source128A. The source 128 emits enough energy so that a portion of the facingsystem melts sufficiently to permit a portion of the fibrous batt 110 tobe pressed into the softened facing material 64. Preferably, the facingmaterial is energized in a cross-hatch or web pattern, according to thetechnology disclosed in commonly assigned and copending U.S. patentapplication Ser. No. 09/088,990, filed Jun. 2, 1998, for whom BharatPatel, Larry J. Grant, Dallas L. Dudgeon, Matthew L. Brokaw, Weigang Qiand Russell Marsh Potter are the inventors, the entirety of which ishereby incorporated by reference. The same preference for softening thefacing material 64 in the cross-hatch or web pattern is true for theembodiment of FIG. 7.

Once the facing material 64 and the fibrous batt 110 leave the first nip(between the rollers 116A and 118A), they begin to decompress. Thisdecompression retards the pressing of the fibrous batt 110 into thesoftened facing material 110, i.e., the decompression promotesdebonding. Fortunately, the ultrasonic heating imparts the minimumenergy to the facing material 64, so that it re-solidifies quicklybefore significant debonding can take place. The optional, butpreferred, second nip (between the rollers 116B and 118B) is locatedclosely enough to the first nip so that the deleterious effects of thedecompression can be minimized before the softened facing material 64can re-solidify. The compression of the second nip is comparable to thefirst nip.

Alternatives to the pinch rollers 116 A, 118A, 116B and 118B includeflat pieces or caterpillar conveyer belts that are similar to theconveyors 112.

Again, in FIG. 10, the facing material 64 is preferably a coextrudedpolymer film, as in the embodiment of FIG. 7. The choice of thematerials for the various layers depends upon the particularcircumstances to which the invention will be applied. However, thebonding layer, e.g., 82 of FIG. 9, should resonate at a first frequencyof ultrasonic radiation to which the other layer(s) is not resonant. Inaddition, the melting point(s) of the other layer(s) should be selectedso that the other layers are not sympathetically melted via conductionheating due to the increase in temperature of the bonding layer.

FIG. 11 is a schematic perspective view of a third apparatus formanufacturing insulation products according to the invention. FIG. 11 issimilar to FIG. 10. The following discussion will concentrate on thedifferences between FIG. 11 and FIG. 10.

Rather than having one roll 114 of facing 64, FIG. 11 has two, namelyrolls 114A and 114B of facings 64A and 64B, e.g., coextruded polymer.The first facing 64A is attached ultrasonically to the top of thefibrous pack 110. The second facing 64B is ultrasonically attached tothe bottom of the fibrous pack 110. In FIG. 11, the ultrasonic radiationsource 128C is the primary energy source for heating the facing 64B. Theultrasonic radiation source 128D is preferably a redundant backup to thesource 128C in the same relationship as source 128B relative to source128A.

If it is desired to have a doubly-faced product as the final product,one might choose to make coatings 64A and 64B different. In this case,the coating 64A might be formulated to be a vapor barrier while thecoating 64B might be formulated to be permeable to water vapor. Thesides could be encapsulated using the technology described below in thediscussion of FIGS. 17 and 15.

The double faces of FIG. 11 could alternatively be attached using theconductive heating system of FIG. 7. In that case, the ultrasonicsources 128A, 128B, 128C and 128D would not be present and the rollers116A and 116B would be heated.

FIG. 13 depicts a simplified schematic perspective view of a fourthembodiment for manufacturing an insulation product according to theinvention. FIG. 13 depicts an apparatus that forms the fibrous packlanes 1708, 1710 and 1712 from a single fibrous pack 110 before thefacings 64A and 64B are applied, either via conduction heating (notshown, but see FIG. 7) or ultrasonic heating (not shown, but see FIG.10). The fibrous pack 110 is vertically slit into the lanes 1708, 1710and 1712 via the blades 1714 and 1716. Only three lanes have beendepicted in FIG. 13. However, any number can be formed depending uponthe circumstances to which the technology is applied.

Before the facings 64A and 64B are applied, gaps 1732 and 1734 areformed between the lanes 1708, 1710 and 1712. Only the facings 64A and64B are present in the gaps 1732 and 1734. The facings 64A and 64B inthe gaps 1732 and 1734 are attached together via a heated nip 1736 andthen slit via (preferably heated) knives 1718 and 1720 to form theencapsulated products 1722, 1724 and 1726 separated by the gaps 1738 and1740.

FIG. 12 depicts the heated nip 1736 of FIG. 13 in more detail as theheated nip 1504. In FIG. 12, a doubly-faced insulation product 1502 hasa gap 1509 that has been formed between fibrous pack lanes 1514 and1512. Heated rollers 1506 and 1508 form a nip that compresses thefacings 64A and 64B together. The temperature of the rollers 1506 and1508 is sufficient to partially melt the facings 64A and 64B together toform a fused portion 1516. Alternatively, the facings 64A and 64B couldbe melted ultrasonically as in FIG. 10. Also alternatively, andpreferably, one of the rollers 1506 and 1508 could be one of the rollers1704 of FIG. 13.

A gap 1510 remains between the facings 64A and 64B, the fused portion1516 and the fibrous pack lanes 1514 and 1512. A (preferably heated)knife 1520 vertically slits the fused portion 1516. Those lanes whichare adjacent to only one other lane are considered to be end lanes. Bycarefully setting the overhang of the facings 64A and 64B relative tothe edge lanes, no cutting of the outermost fused portions should beneeded. FIG. 13 has an advantage that only the alignment between the endlanes and the edges of the facings must be of high accuracy. Alignmentbetween the other lanes, i.e., the non-edge lanes, and the facing needonly be of low accuracy. In contrast, the conventional art applies asingle discrete facing to each lane, which requires high accuracy foreach lane.

If a one inch flange on each side is desired, for example, then the gapbetween the lanes should be about 3.5 inches, which corresponds to therecovered/decompressed height of the fibrous pack plus two inches. Theheated nip 1504 should be about two inches wide the knife 1520 wouldslit the fused portion in half.

The fourth embodiment produces an insulation product that has a facingadhered to both major surfaces, where the facings are connected togetherto enclose the fibrous pack. Though enclosed, the minor faces are notattached to the facings 64A and 64B. This represents an alternative tothe encapsulation technology of FIG. 7.

The principle and mode of operation of this invention have beendescribed in its preferred embodiments. However, it should be noted thatthis invention may be practiced otherwise than as specificallyillustrated and described without departing from its scope.

What is claimed is:
 1. An apparatus for attaching at least two facingsto a mineral fiber batt, the apparatus comprising: a first facingsource; a first roller arranged to place a first facing from said firstfacing source into contact with a first side of said batt; a firstheating source operable to heat a region through which passes said firstfacing while in contact with said batt, the heating by said firstheating source being sufficient to melt a portion of said first facingonto fibers of said batt; a second facing source; a second rollerarranged to place a second facing from said second facing source intocontact with a second side of said batt; and a second heating sourceoperable to heat a region through which passes said second facing whilein contact with said batt, the heating by said second heating sourcebeing sufficient to melt a portion of said second facing onto fibers ofsaid batt; at least one nip to compress said first and second facingtogether in said at least one gap; and at least one third heating sourceto heat a region through which passes said first facing in contact withsaid second facing, the heating by said third heating source beingsufficient to melt together a portion of said first facing and a portionof said second facing to form a fused facing portion. wherein said firstand second rollers cause said at least one gap to be enclosed by saidfirst and second facings and edges of the corresponding lanes of saidbatt.
 2. The apparatus of claim 1, wherein said first and second heatingsources provide one of conduction heating and ultrasonic heating.
 3. Theapparatus of claim 1, wherein said first facing and said second facingare applied to opposite sides of said batt thus forming a doubly-facedbatt.
 4. The apparatus of claim 3, the apparatus further comprising atleast one pre-slicing mechanism to slit said batt into at least twolanes having at least one gap therebetween prior to said batt reachingsaid firsthand second rollers.
 5. An apparatus for attaching at leasttwo facings to a mineral fiber batt comprising: a first facing source; afirst roller arranged to place a first facing from said first facingsource into contact with a first side of said batt; a first heatingsource operable to heat a region through which passes said first facingwhile in contact with said batt, the heating by said first heatingsource being sufficient to melt a portion of said first facing ontofibers of said batt; a second facing source; a second roller arranged toplace a second facing from said second facing source into contact with asecond side of said batt; and a second heating source operable to heat aregion through which passes said second facing while in contact withsaid batt, the heating by said second heating source being sufficient tomelt a portion of said second facing onto fibers of said batt; at leastone nip, located near at least one edge of said batt, to compress theoverhanging portions of said first and second facings together; and atleast one third heating source to heat a region through which passessaid first facing in contact with said second facing, the heating bysaid third heating source being sufficient to melt together a portion ofsaid first facing and a portion of said second facing.